Treatment of cellulosic textile materials



Patented Non-19, 1946 TREATMENT OF CELLULO SIC TEXTILE MATERIALS HoraceJames Hogan, Coventry, and Edwin Holroyd Sharples, Kenilworth, England,as-

slgnors to Courtaulds Limited, London, land, a British company Eng- -NoDrawing. Application November 6, 1944, Se-

it?! No. 562,264. In Great Britain January 12,

4 Claims. 1 This invention relates to treating cellulosic textilematerials in order to obtain level dyeings when these materials areknitted into hosiery or woven into fabrics.

It is well known to subject cellulosic yarn or thread to a twistingoperation and subsequently to set the twist by treatment with steam.When cellulosic yarns are subjected to steaming, there is a lowering ofthe affinity of the yarn for dyestuffs, which lowering is dependent uponthe temperature and time of the steaming and the degree of wetness oithe yarn. When steaming the yarn on bobbins, there is a tendency for theouter layers of yarn to be more heavily steamed than the inner layersand also there is a possibility of drops of condensed water falling onthe yarn so that there is a considerable tendency in the steamingprocess for variations in dyeing aflinity to be produced throughout thebobbin and on making this unevenly steamed yarn into hosiery andsubsequently dyeing, the material exhibits marked differences in shade.

The object of the present invention is to obtain a yarn which will bestabilised towards the steam treatment so that any difierences occurringduring the steaming process will not appreciably 2 artificial origin;for example, the process may be applied to cotton or to artificial yarnsof cellulose regeneratedfrom viscose or cuprammonium cellulosesolutions.

The following example illustrates the present invention, but theinvention is not restricted to this example:

' Example Cakes of bleached, desulphurised 75 denier l8 filament viscoseartificial silk are, without drying; placed in water in an autoclave andthe temperature is raised to 120 centigrade. The treatment is continuedfor minutes, the cakes are removed irom the autoclave and dried. Theyarn is wound from the cake on to bobbins and is then given a twist of15 turns per inch. Thetwlsted yarn is then steamed to set the twist.'The affect the dyeing affinity of the yarn, and therebilises the yarnso that any differences in the steaming operation do not deleteriouslyaflect the dyeing afiinity. The treated yarn is knitted or woven intofabric which on subsequent dyeing gives level'shades. I V

The conditions of time and temperature used in carrying out thisinvention are interdependout, a higher temperature giving a desiredresult m a shorter time. It is sometimes preferred to add a little soapor other alkaline softening agentto the water in which the yarn isheated.-

The process of the present invention is applicable to cellulosic textilematerials of natural or 2. In the production of a dyed twisted celluloseyarn as claimed in claim 1 the addition of a 1 small proportion of soapto the water used. in the preliminary step.

3. In the production of a dyed twisted regen I .erated cellulose yarnthe combination with the steps of drying, twisting, setting the twist bya steaming operation and dyeing, of a preliminary step of treatment inwater under pressure at a temperature above 100 centigrade to stabilisethe dyeing amnity of the yarn against the efl'ects of uneven steaming.

4.11: the production of a. dyed twisted regenerated cellulose yarnasclaimed in claim 8 the addition 01' a small proportion of soap to thewaterused in the preliminary step.

noascn .mms HEGAN.

EDWIN nomorn amazes.

